1170S6035 - ER70S-6 .035 Mild Steel Solid MIG Wire 11lb Spool

Technical Overview: ER70S-6 Solid Carbon Steel Wire

The ER70S-6 is a copper-coated, solid mild steel welding wire formulated to meet AWS A5.18 specifications. This 0.035-inch (0.9 mm) diameter wire is supplied on an 11 lb (5 kg) spool, ideal for medium-duty GMAW applications. The "S6" classification indicates a chemical composition rich in silicon (0.80–1.15%) and manganese (1.40–1.85%). These elements act as potent deoxidizers, scavenging oxygen from the weld pool and allowing for successful welding over surfaces with moderate amounts of mill scale, rust, or oil.

Arc Characteristics and Shielding Gas

This wire is designed for use with Direct Current Electrode Positive (DCEP) polarity. It exhibits excellent feedability due to its consistent diameter control and high-quality copper coating, which reduces friction in the liner and enhances current transfer. The wire operates effectively in both Short Circuit Transfer (dip transfer) and Spray Transfer modes, depending on the voltage and shielding gas used.

• 100% CO2: Provides broad penetration profiles and is cost-effective, though it may produce slightly more spatter.
• 75% Argon / 25% CO2 (C25): Promotes a smoother arc, reduced spatter, and a visually appealing bead profile, ideal for thinner gauge materials and out-of-position welding.

Mechanical Properties and Applications

Weld deposits made with ER70S-6 typically exhibit a minimum tensile strength of 70,000 psi (480 MPa), meeting the requirements for structural integrity in mild steel applications. The high silicon content also contributes to increased fluidity of the weld puddle, ensuring excellent wetting at the toes of the weld and reducing the risk of lack of fusion. This wire is the preferred choice for single-pass and multi-pass welding on carbon steels such as ASTM A36, A285, A515, and A516.